Add a GPU Fragment-Shader Raster Layer for terra::SpatRaster

Streams raw Float32 raster values (GLMR binary packet) directly into a WebGL2 R32F floating-point texture. Colormapping, hillshading, min/max contrast stretching, thresholding, and live pixel value inspection happen entirely on the GPU in 0 ms without re-rendering PNGs in R.

Usage

add_raster(
  map,
  raster = NULL,
  palette = "viridis",
  opacity = 0.85,
  domain = NULL,
  hillshade = FALSE,
  max_cells = 1000000L,
  bands = 1L,
  bbox = c(-75, 45, -71, 48),
  id = NULL,
  group = NULL,
  legend = TRUE
)

Arguments

map: A glmap widget or glmap_proxy.
raster: A terra::SpatRaster or numeric matrix.
palette: Color palette name ("viridis", "terrain", "magma", "turbo", "plasma", "RdYlBu").
opacity: Raster opacity (0 to 1).
domain: Optional numeric c(min, max) value range for colormap stretching.
hillshade: Logical; whether to compute real-time GPU surface normal hillshading in the fragment shader.
max_cells: Maximum raster cells before automatic overview aggregation (default 1,000,000).
bands: Integer band index or indices to stream.
bbox: Bounding box c(xmin, ymin, xmax, ymax) when raster is a plain matrix.
id: Layer ID string.
group: Layer group name.
legend: Logical; whether to display a color ramp legend and interactive GPU raster controls.